Molding machine and mold for centrifugal casting of annular bodies



N. W. WEBB Feb. 17, 1942.

MOLDING MKCHINE AND MOLD FOR CENTRIFUGAL CASTING OF ANNULAR- BODIESFiled Aug. 2, 1940 PEA.

/INVENTOR NW WEBB.

NEYLEEI area of the plate 23 is out of contact 1n the drawing; Fig. 1 isa front elevation of a centrifugal casting machine accprding to theillustrated exemplary embodiment of the invention. Fig. 2 is a sideelevation of one end of the machine and showing the centrifugal mold atthis end in vertical section, and showing in dotand-dash lines theposition of one of the mold.

parts during the reversal operation.

Fig. 3 is a view partially in side elevation illustrated, the other endbeing identical and carrying upon the mold supporting shaft anothercentrifugal mold unit similar to that illustrated.

With this type of double-mold machine two --plates may be castsimultaneously, or a plate cast at one end while the mold at the otherend is being cooled, provided with mold dressing, and otherwise preparedfor casting another plate.

with a recess 28 having a peripheral wall is which corresponds exactlyto the recess and wall 26 of. the plate 23, the diameter of the plate 26however being less than the diameter of the plate 23 and equal to thediameter of the seating pocket formed by the flange 21, so that it seatstherein in centralized relation and whereby the inwardly disposedrecesses 25 and 28 of the two plates constitute the annular mold cavity.

The plate 24 is provided centrally with the hole 30 into which thepouring spout 3| projects, molten metal being poured into this spoutwhich fiows downwardly into the centrifugal mold to form an annularplate casting. It will be understood that the pouring spout 3| ismounted upon a suitable fixture, as for instance a roller carrier or aswinging arm, so that it can be readily moved into and out ofplacerespectively during the casting operation of the mold, and the openingand reversing of the mold parts.

The two mold parts are secured in the mold carrier by a series of boltstuds 32 having re- It will be understood howeverthat the invention isnot limited to this particular type of machine, but may be incorporatedin single mold types. I

A mold driving shaft H is journaled at each end of the base B0 in abearing block l2 and carries a pulley i3 driven by a belt 14 from apulley l5 provided on an upper counter-drive shaft I5 journaled at eachend in a, bearing fixture l5. mounted upon a frame It upon each end ofthe base in, the shaft l5 being driven from any suitable source ofpower.-

The keyed plate carrier i8,

shaft ii 'projects at each end, and has thereon the hubll of thecircular mold which is provided at its rim witha cylindrical flange l9having a slot 20 atone point in which the transporting and manipulatingsupporting eyes of the mold plates are engaged, as will Upon the innerwall of the mold carrier there is provided an annular seating rib 2|inwardly spaced from the rim l9 and provided at its outer periphery witha beveled seating surface 22.

Thetwo-part 'mold consists 'of an inner periphery rimmed diaphragmaticmold plate 23 and an outer peripherally rimmed diaphragmatic mold plate24, the inner mold plate 23 being provided at each of its faces with amold cavity forming recess 25, the outer wall 28 of which is beveled incorrespondence with the beveled bearing surface 22, so that in theassembled relation in the platecarrier |8the wall surface 26 wedginglyseats upon the seating surface 22, while the recess 25 and the wall 23at the other side constitute the face and outer peripheral edge ofone-half of the mold cavity. The central with the central area of themold carrier definedby the annular-seat 22,. so that there is norestriction of the bulging action which takes place in the 2 plate 23during the casting operation, and as will hereinafter more fully appear.The rim of the mold. part 23 is provided at each side with a projectingshoulder flange 21 forming an annular pocket inwhich' the rim of theouter or cover mold plate 23 is adapted to seat. The outer mold plate 24is also provided at each face supported presently more fully appear..

taining lugs 33 mounted thereon and which are tightened against theouter surface of the rim IQ of the carrier and the outer surface of therim of the'outer or cover plate mold part 24 by means of nuts 34. The'mold parts 23 and 24 are respectively provided with eye members 35 and35 which project into the open space 20 of the rim i9, and which areadapted to be engaged by the conveyer means, presently to be more fullydescribed, for removing the mold parts from the mold carrier.

Above the machine then is mounted an inverted T-shape trolley trackmember 31 carrying a pair 'of roller conveyer members 38 and 39 uponwhich are suspended the respective conveyer hook members 40 and 4|connected thereto by turn-buckles and 43, and which hook members areadapted to be brought into engaging relation with the-eye members 35 and36.

Upon completion of the molding operation the mold is first disposed sothat the eye members 35 and 36 are at the top, as shown in the drawing,and thereupon the lugs 33 are disengaged by backing of! the nuts 34, thetwo hook members Mi and 4| being first engaged with the respective eyes35 and 36 of the two mold parts. The mold parts are thereupon movedoutwardly from the mold carrier and are then separated to allow the castplate to drop therefrom, it being pire before separating the mold partsto allow the cast plateto cool for a suitable period if this is found tobe desirable.

The two mold parts are thereupon reversed by individually turning them-by' means of the turnbuckles of the conveyer, so that the recesses 25and 28 which during the preceding molding operation were disposedinwardly and constituted the molding cavity are disposed outwardly.Before reversing the cavity surfaces may have a suitable mold dressingapplied if this is found to be desirable. The recesses were outwardlydisposed now constitute the molding cavity. The two mold parts arethereupon moved into relation with. the mold carrier l8 and are clampedin place by means of the lugs 33 and the nuts 34, the hooks '40- and IIare disconnected, and the machine is ready for the next castingoperation.

By thus alternating the molding faces of' the two diaphragmatic platesthe bulging action 25 and 23 which v 2,278,238 3 which takes placethrough the differential ther gradient between the inner andoutermold'surfaces is compensated for by the succeeding mold-- ing operation,the surfaces which are bulged outas the degree -of bulge during a singlecasting is not suflicient to materially aflfect th thickness of theplate 'the mold will continue to produce satisfactory uniform castingsto, any desired quantity, and with a considerable saving in timeandproduction costs.

In Fig. 4 I have illustrated a modified form of the mold plate in whichthe recesses 25" and 28 are slightly inclined toward the center so thatthe mold cavity produces a plate which is of gradually increasingthickness toward the center.

The purpose'of this is to' compensate for th differential indensity inthe material between the inner and outer peripheries of the cast platedue to the centrifugal action which causes thelmetal at the outerperiphery to become denser from the weight of the metal building up atthe inner 'mal strains set up by the steep temperature periphery. Thecast plate is thereupon-adapted to be rolled to uniform thickness toequalize the difierential density.

I have illustrated and described'preferred and.

satisfactory embodiments of the invention, but it will be understoodthat changes may be made therein, within the spirit and scope thereof,as defined in the appended claims.

Having thus described my invention,

1. In a molding machine for the centrifugal.

casting of annular centrally apertured discus plates, a verticallydisposed rotatable mold car rier rotatable about a horizontal axis, atwo-part centrifugal casting mold comprising a pair of circular moldparts, each consisting of a circular diaphragmatic plate havingcomplementary andv identical faces .at each of its sides and a circularhat 1 Y claim and desire to secure by Letters Patent is:

rim surrounding said plate and projecting to an equal extent at eachside thereof to constitute the peripheral wall of a circular mold recessat each side, the recesses of both of said mold parts being of the samediameter, and each of said mold parts being individually reversable todispose the mold recess at either of its sides in either facing ornon-facing relation to the other mold part, one of said mold partshaving an opening for receiving molten metal, and means for removablysecuring said pair of mold parts'to said carrier with the mold recessesat their facing sides constituting a circular mold cavity and the moldrecesses at their other sides constituting spaces in which thediaphragmatic plates may bulge during the casting operation.

2. In a molding machine for the centrifugal casting of annular centrallyapertured discus plates, a vertically disposed rotatable mold carrierrotatable about a horizontal axis and having an annular beveled seatingrib formed upon its forward face, a two-part centrifugal casting moldcomprising a pair of circular mold parts, each consisting of a circulardiaphragmatic plate having complementary and identical faces at each ofits'sidcs and a circular rim surrounding said plate and projecting to anequal extent at each side ing molten metal; and means for removablysecuring said pair of mold parts to said carrier with the mold recessesat their facing sides constituting a circular mold cavity and the moldrecesses

